Automatic set-back control for gas water heater



FIG. 1 is a perspective view of an automatic set-back control for gas water heaters showing my new design;

FIG. 2 is a left side elevational view thereof, the right side being a mirror image thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a bottom plan view thereof; 

The ornamental design for an automatic set-back control for gas water heaters, substantially as shown. 